This invention relates to a clothes dryer. In its more specific aspect, this invention relates to a tumbler or cylinder for a commercial clothes dryer having components of different types of steel.
A typical commercial clothes dryer, including gas-fired, electric heated, and steam heated, comprises a housing of substantially rectangular configuration for holding such things as the motor, piping, duct work, valving, and the like, essential for the operation of the dryer. The central feature of the dryer in so far as the consumer or end user is concerned is the cylinder, sometimes referred to as the basket or tumbler, which is substantially cylindrical and horizontally disposed in the housing. In operation, the cylinder rotates about its central horizontal axis. The front end or forward end of the tumbler is open, and a door, which is hingedly mounted on the housing, provides access to the cylinder. A glass window in the door, known as the door glass but may be plastic rather than glass, allows the consumer to view the tumbler and its contents. The load capacity for the cylinder of a commercial clothes dryer may range from about 30 pounds to about 200 pounds, most typically being about 30-75 pounds, and the tumbler may measure from about 30-40 inches in diameter and about 30-40 inches deep.
The basket or cylinder is substantially cylindrical configuration having a reticulated or open network wall. A plurality of vanes or ribs, usually four, are radially disposed in the tumbler and extend for a short distance from the interior of the wall, The cylinder is closed at the rear or back with a steel sheet. The tumbler, including the vanes and backing, are made of galvanized steel, or galvalume, which enhances the wear and inhibits the corrosion of the base metal, e.g., steel. However, the finishing on the base metal, i.e., galvanizing, detracts considerably from the appearance, which is a negative to the consumer or user. Because the cylinder wall is reticulated, the largest surface area is the steel backing, and the eye focuses largely on this backing. Moreover, although the finishing on the base metal, such as the galvanizing, enhances the properties of the steel, it nevertheless has its limitations as to heat conductivity and corrosion resistance. This is particularly true with clothes dryers that operate at elevated temperatures. Also, harsh chemicals used in the laundering of clothes frequently are not adequately or completely rinsed from the clothes, and when placed in the dryer, these chemicals attack the finish coating and the steel. As a consequence, the backing in particular, which has the larger surface area and receives the brunt of the impact, will deteriorate faster and therefore lose its appeal to the consumer or end user.
This invention has therefore as its purpose to provide in a clothes dryer a cylinder exhibiting improved heat conductivity and corrosion resistance, and yet maintain its aesthetic appeal.
Broadly, my invention provides a clothes dryer comprising a housing having a horizontally disposed substantially cylindrical tumbler or basket arranged in the housing so as to be rotatable about its center longitudinal axis. The wall of the cylinder is reticulated, and a plurality of vanes or ribs extend radially from the interior of the wall for a short distance to facilitate tumbling of the clothes. This part of the cylinder is formed of a galvanized steel, such as a cold rolled steel with a galvanized coating, but it should be understood that the term xe2x80x9cgalvanizexe2x80x9d or xe2x80x9cgalvanizingxe2x80x9d as used herein and in the appended claims is not limited to a zinc coating, but may include other zinc alloy coatings. The cylinder has a forwardly disposed open end, and a door is hingedly mounted to the housing to allow access to the cylinder at the open end. The oppositely disposed end of the bucket, that is the end opposite to the open end, is provided with a stainless steel sheet having a substantially mirror finish as viewed from the forward and.
The backing is comprised of a stainless steel sheet having at least about 12 percent by weight chromium, preferably about 14 to 18 percent by weight, but the total chromium can vary depending upon other alloying elements. For any such tumbler, the surface area is predominantly that of the stainless steel backing, because the reticulated wall is an open network or a perforated wall, and therefore the metal network has a smaller surface area. The stainless steel backing is provided with a substantially mirror finish, so that when one looks into the basket or through the glass of the door, the eye will focus on the bright surface. Further, the stainless steel sheet, or chrome steel sheet, is at least about 22 gauge, but the gauge for the sheet can vary depending upon such factors as the size of the cylinder, the temperature of operation, and the life expectancy for the cylinder. Also, the back sheet typically receives the brunt of the impact from the clothes in the dryer, and the sheet must be of sufficient thickness to resist impact without deforming permanently.